1. Field of the Invention
The present invention relates to a lithium ion capacitor, and more particularly, to a method of manufacturing a lithium ion capacitor to perform a cleaning process of a terminal after performing a pre-doping process of lithium ions by allowing an anode to be directly in contact with a lithium supply source.
2. Description of the Related Art
In general, electrochemical energy storage devices are core parts of finished products, which are essentially used in all mobile information communication devices and electronic devices. In addition, the electrochemical energy storage devices will be used as high quality energy sources in new and renewable energy fields that can be applied to future electric vehicles and mobile electronic devices.
The electrochemical capacitor among the electrochemical energy storage devices can be classified into an electrical double layer capacitor using an electrical double layer principle and a hybrid super capacitor using an electrochemical oxidation-reduction reaction.
Here, although the electric double layer capacitor has been used for a field required for a high power energy property, the electric double layer capacitor has a problem such as a small capacitance. On the contrary, the hybrid super capacitor has been studied for a new method to improve the capacitance property of the electric double layer capacitor. Particularly, the lithium ion capacitor (LIC) among the hybrid super capacitors can have an accumulative capacitance in the degree of 3 times to 4 times in comparison with the electric double layer capacitor.
A process of forming the lithium ion capacitor may include a stacking process to form an electrode stacking material by sequentially stacking a cathode with a sheet shape, a separating layer and an anode, a welding process to weld the terminals of the cathode and the terminals of the anode, a pre-treatment doping process to pre-dope the lithium ions into the anode by immerging the electrode stacking material into an electrolyte and a sealing process to seal the electrode stacking material with aluminum.
Here, the process to pre-dope the lithium ions into the anode may be performed by immerging into the electrolyte solution after lithium metal layers are provided on the most top layer and the most bottom layer of the electrode stacking material, respectively.
At this time, in order to smoothly supplying the lithium ions to the anode during the pre-doping process, the collectors provided in the cathode and the anode must have a mesh shape. In this result, there is a problem to increase an inner resistance of the lithium ion capacitor.
And also, since the lithium metal layers are provided on both ends of the electrode stacking material, there is a problem that the lithium ions are uniformly doped into an overall of the stacked anode.
And also, since a time until the lithium ions are uniformly doped into the anode provided inside of the electrode stacking material is approximately 20 days, there is a problem to be applied for a mass production.